The Launch of SA-1

Prelaunch preparation began at 7:00 a.m. on 26 October 1961. Mechanical
Office tasks that morning included inspection of the high pressure gas panel,
cable masts, and fuel masts; ordnance installation; and preparation of the
holddown arms. At 12:30 p.m., Thomas Pantoliano's 12-man propellants section
checked out the RP-1 fuel facility while Andrew Pickett's team pressurized the
helium bottle. RP-1 loading began an hour later. The propellant team filled the
launch vehicle's tanks to the 10% level, using a slow, manual procedure of
approximately 750 liters per minute to check for leaks. A leak in the fuel mast
vacuum breaker was easily repaired, and at 2:30 p.m. the launch team cleared the
pad for the automatic "fast fill" operation. Fuel flowed into the launch vehicle
at 7,570 liters per minute, reaching the 97% level in about 35 minutes. The
propellants team then reverted to the "slow fill" procedure. As the design of
the Saturn included a fuel drainage system, Pantoliano's crew placed 103% of the
required RP-1 aboard the Saturn. Just before launch, the propellants team would
take a final density reading and drain sufficient kerosene to achieve the
desired level.35

The ten-hour countdown started at 11:00 p.m. as LC-34 switched to the Cape's
emergency generating plant. This facility supplied the launch team a current
relatively free of the fluctuations common in commercial power. The Saturn's
electrical circuits and components began warming up when vehicle power was
applied at T-570 - 570 minutes before launch time exclusive of holds. Five
minutes later the measuring panel operator turned on the eight telemetry
channels. A series of calibration checks followed. At T-510 range and launch
officials initiated an hour of radar checks.36

Loading of liquid oxygen started after 3:00 a.m. on the 27th (T-350). The
Saturn's LOX tanks were 10% filled to check for leaks in the launch vehicle or
in the 229-meter transfer line, as well as to precool the line for the fast flow
of super-cold LOX. While the automatic fast fill from the 473,000 liter LOX
storage tank employed a centrifugal pump, the 10% precooling operation relied on
the pressure in the reservoir. The 10% level in the Saturn's tanks was
maintained for the next four hours by feeding LOX from the 49,000-liter
replenishing tank.37

Testing of command and communication systems began at T-270. The flight
control panel operator activated the guidance system's stabilized platform, the
ST-90, to check pitch, roll, and yaw response. Ten minutes later the network
panel operator placed the vehicle on internal power to ensure that the Saturn's
batteries functioned properly. Meanwhile other engineers conducted Azusa, UDOP,
radar, and telemetry checks. The operation was over by T-255, and the launch
vehicle was returned to external power.38

Two hours from the 9:00 a.m. scheduled liftoff, an unfavorable weather report
prompted launch officials to call a hold. When the count resumed at 7:34 a.m.,
the launch team rolled the service structure back to its parking area, 180
meters from the rocket. The propellants team set up the LOX facility for fast
fill at T-100. The order to clear the pad came 20 minutes later; the blockhouse
doors swung shut at T-65. One hour from launch the pad safety officer gave his
clearance and the propellants team initiated a 6.5-minute precool sequence, a
slow fill to recool the main LOX storage tank line, which had not been in use
for four hours. When the "Precool Complete" light flashed on, the LOX facility's
pump began moving 9,500 liters per minute into the Saturn. In 30 minutes the
tanks were 99% full. LOX loading changed over to the replenish system. An
adjust-level drain*
had already been made on the RP-1 tanks, bringing the fuel level down to 100%.39

Launch officials, concerned that a patch of clouds over the Cape might
obscure tracking cameras, called a second hold at 9: 14 a.m. A northeast breeze
was soon clearing the skies, and within half an hour the countdown resumed.
During the last 20 minutes, the launch team made final checks of telemetry,
radar, and the command network. Automatic countdown operations commenced at
T-364 seconds. A sequencer or central timing device controlled a series of
electrical circuits by means of relay logic; i.e., if event A occurred (e.g.,
opening a valve), the sequencer triggered event B, and so on through the
required functions to liftoff. The sequencer monitored tank, hydraulic, and pump
pressures; ordered a nitrogen purge of the engine compartment; and closed the
LOX tank vents to pressurize the liquid oxygen. The Saturn vehicle switched to
internal power at T-35 seconds. Ten seconds later the sequencer ejected the long
cable mast. The pad flush command at T-5 seconds began a flow of water around
the launcher base. At that time, a number of possible malfunctions (a premature
commit signal, insufficient thrust in one or more engines, rough combustion,
short mast failure, detection of fire, or voltage failure) could still cause the
automatic programmer to terminate the countdown.40

Away from launch complex 34, Cape watchers gazed uncertainly at the Saturn
rocket as the countdown neared completion, No previous maiden launch had gone
flawlessly, and the Saturn C-1 was considerably more complicated than earlier
rockets. LOD officials gave the rocket a 75% chance of getting off the ground, a
30% chance of completing the eight-minute flight. Although odds on a pad
catastrophe were not quoted, launch officials acknowledged their vulnerability.
With the construction of LC-37 barely begun, a pad explosion could delay the
Saturn program a year. Critics had questioned the wisdom of the clustered
booster design. Propellant pumps were supposedly reaching design limits and the
Saturn C-1 had 16 pumps in eight engines. Local wags derisively referred to the
SA-1 launch as "Cluster's Last Stand."41

Saturn backers, while expressing confidence in the rocket, were concerned
about its launch effects. During test firings at Redstone Arsenal, residents 12
kilometers away had reported shattered windows and earth tremors. The launch
team had set up panels and microphones at the Cape to register the Saturn's
shock and sound waves. At the press site, 3 kilometers from pad 34, reporters
were issued ear plugs as a precautionary measure. LOD officials had assured
local residents that fears of the rocket were exaggerated. Still, everyone
wondered what it would be like. The moment of truth came at 10:06 a.m. Contrary
to popular belief, no one pushed a firing button to send SA-1 on its way. Launch
came when the sequencer ordered the firing of a solid propellant charge. The
gases from the ignition accelerated a turbine that in turn drove fuel and LOX
pumps. Hydraulic valves opened, allowing RP-1 and LOX into the combustion
chambers, along with a hypergolic fluid that ignited the mixture. The engines
fired in pairs, developing full thrust in l.4 seconds. A final rough combustion
check was followed by ejection of the LOX and RP-1 fill masts from the booster
base. The four hold-down arms released the rocket 3.97 seconds after first
ignition. SA-1 was airborne.

Liftoff of Saturn I. Note the long cable mast falling away on the
right.

Spectators saw a lake of flame, felt the rush of a shock wave, and then heard
the roar of the eight engines. Trailer windows at the viewing site shook in
response to the Saturn's power. Yet for many of the thousands watching the
launch, the roar was a letdown. Reporters thought the sound equaled an Atlas
launch viewed at half the distance.**
The Miami Herald headline the next morning read: "Saturn Blast 'Quieter' Than
Expected."42

Although the Saturn's roar failed to meet expectations, the human noise at
LC-34's control center was impressive. Bart Slattery, a NASA information
officer, told reporters that when the rocket passed maximum Q (point of greatest
aerodynamic pressure) at about 60 seconds into the flight, "all hell broke loose
in the blockhouse." Kurt Debus's face reflected the happy sense of
accomplishment hours later when he informed the press that it had been a nearly
perfect launch.43

The success was particularly welcome to the Kennedy administration, coming at
a time of high tension between the United States and the Soviet Union. The
raising of the Berlin Wall had stunned the Western world in August 1961.
President Kennedy had responded with a partial mobilization of U.S. reserve
forces, but most political analysts considered the events a Russian victory. In
late October, as the Soviet Union prepared to test a 50-megaton H-bomb, the
President had proposed a massive fallout shelter program. On the day of the SA-1
launch, Russian tanks moved into East Berlin for the first time in several
years.

The space race was an important element in a Cold War that threatened to turn
hot. With the success of the Saturn booster, the United States had achieved a
launch capability of 5.8 million newtons (1.3 million pounds of thrust). Space
reporters were quick to point out the limits of the American success. The Soviet
Union already had workable upper stages for their first stage. Furthermore, the
current Russian tests in the Pacific would likely result in sizable booster
advances. Despite these caveats, commentators agreed that SA-1 was an important
step toward a lunar landing.44

* Establishing an exact ratio of RP-1 to LOX
was important since simultaneous depletion of propellants at cutoff was desired.
Flight data later indicated a 0.4% deviation in the RP-1 fuel density sensing
system, 0.15% above design limits. Too much LOX (400 kilograms) and not enough
RP-1 (410 kilograms} were therefore loaded. The error contributed to a premature
cutoff 1.6 seconds ahead of schedule.

** Marshall Center scientists, after studying
readings taken in nearby communities during launch, explained that weather
conditions were such that sound was absorbed by the atmosphere. As a result,
sound levels were less than those experienced during static firings at
Huntsville.